Move CanGetMempool test from testnet to mainnet
Move CanGetMempool test from testnet to mainnet

lontivero/NBitcoin,stratisproject/NStratis,dangershony/NStratis,MetacoSA/NBitcoin,NicolasDorier/NBitcoin,HermanSchoenfeld/NBitcoin,thepunctuatedhorizon/BrickCoinAlpha.0.0.1,MetacoSA/NBitcoin